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  1. 02 Nov, 2011 18 commits
    • Andrea Arcangeli's avatar
      powerpc: get_hugepte() don't put_page() the wrong page · 405e44f2
      Andrea Arcangeli authored 
      "page" may have changed to point to the next hugepage after the loop
completed, The references have been taken on the head page, so the
put_page must happen there too.

This is a longstanding issue pre-thp inclusion.

It's totally unclear how these page_cache_add_speculative and
pte_val(pte) != pte_val(*ptep) checks are necessary across all the
powerpc gup_fast code, when x86 doesn't need any of that: there's no way
the page can be freed with irq disabled so we're guaranteed the
atomic_inc will happen on a page with page_count > 0 (so not needing the
speculative check).

The pte check is also meaningless on x86: no need to rollback on x86 if
the pte changed, because the pte can still change a CPU tick after the
check succeeded and it won't be rolled back in that case.  The important
thing is we got a reference on a valid page that was mapped there a CPU
tick ago.  So not knowing the soft tlb refill code of ppc64 in great
detail I'm not removing the "speculative" page_count increase and the
pte checks across all the code, but unless there's a strong reason for
it they should be later cleaned up too.

If a pte can change from huge to non-huge (like it could happen with
THP) passing a pte_t *ptep to gup_hugepte() would also require to repeat
the is_hugepd in gup_hugepte(), but that shouldn't happen with hugetlbfs
only so I'm not altering that.
Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      405e44f2
    • Andrea Arcangeli's avatar
      powerpc: remove superfluous PageTail checks on the pte gup_fast · 2839bdc1
      Andrea Arcangeli authored 
      This part of gup_fast doesn't seem capable of handling hugetlbfs ptes,
those should be handled by gup_hugepd only, so these checks are
superfluous.

Plus if this wasn't a noop, it would have oopsed because, the insistence
of using the speculative refcounting would trigger a VM_BUG_ON if a tail
page was encountered in the page_cache_get_speculative().
Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2839bdc1
    • Andrea Arcangeli's avatar
      mm: thp: tail page refcounting fix · 70b50f94
      Andrea Arcangeli authored 
      Michel while working on the working set estimation code, noticed that
calling get_page_unless_zero() on a random pfn_to_page(random_pfn)
wasn't safe, if the pfn ended up being a tail page of a transparent
hugepage under splitting by __split_huge_page_refcount().

He then found the problem could also theoretically materialize with
page_cache_get_speculative() during the speculative radix tree lookups
that uses get_page_unless_zero() in SMP if the radix tree page is freed
and reallocated and get_user_pages is called on it before
page_cache_get_speculative has a chance to call get_page_unless_zero().

So the best way to fix the problem is to keep page_tail->_count zero at
all times.  This will guarantee that get_page_unless_zero() can never
succeed on any tail page.  page_tail->_mapcount is guaranteed zero and
is unused for all tail pages of a compound page, so we can simply
account the tail page references there and transfer them to
tail_page->_count in __split_huge_page_refcount() (in addition to the
head_page->_mapcount).

While debugging this s/_count/_mapcount/ change I also noticed get_page is
called by direct-io.c on pages returned by get_user_pages.  That wasn't
entirely safe because the two atomic_inc in get_page weren't atomic.  As
opposed to other get_user_page users like secondary-MMU page fault to
establish the shadow pagetables would never call any superflous get_page
after get_user_page returns.  It's safer to make get_page universally safe
for tail pages and to use get_page_foll() within follow_page (inside
get_user_pages()).  get_page_foll() is safe to do the refcounting for tail
pages without taking any locks because it is run within PT lock protected
critical sections (PT lock for pte and page_table_lock for
pmd_trans_huge).

The standard get_page() as invoked by direct-io instead will now take
the compound_lock but still only for tail pages.  The direct-io paths
are usually I/O bound and the compound_lock is per THP so very
finegrined, so there's no risk of scalability issues with it.  A simple
direct-io benchmarks with all lockdep prove locking and spinlock
debugging infrastructure enabled shows identical performance and no
overhead.  So it's worth it.  Ideally direct-io should stop calling
get_page() on pages returned by get_user_pages().  The spinlock in
get_page() is already optimized away for no-THP builds but doing
get_page() on tail pages returned by GUP is generally a rare operation
and usually only run in I/O paths.

This new refcounting on page_tail->_mapcount in addition to avoiding new
RCU critical sections will also allow the working set estimation code to
work without any further complexity associated to the tail page
refcounting with THP.
Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Reported-by: default avatarMichel Lespinasse <walken@google.com>
Reviewed-by: default avatarMichel Lespinasse <walken@google.com>
Reviewed-by: default avatarMinchan Kim <minchan.kim@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      70b50f94
    • Linus Torvalds's avatar
      Merge branch 'next/soc' of git://git.linaro.org/people/arnd/arm-soc · 994c0e99
      Linus Torvalds authored 
      * 'next/soc' of git://git.linaro.org/people/arnd/arm-soc: (21 commits)
  MAINTAINERS: add ARM/FREESCALE IMX6 entry
  arm/imx: merge i.MX3 and i.MX6
  arm/imx6q: add suspend/resume support
  arm/imx6q: add device tree machine support
  arm/imx6q: add smp and cpu hotplug support
  arm/imx6q: add core drivers clock, gpc, mmdc and src
  arm/imx: add gic_handle_irq function
  arm/imx6q: add core definitions and low-level debug uart
  arm/imx6q: add device tree source
  ARM: highbank: add suspend support
  ARM: highbank: Add cpu hotplug support
  ARM: highbank: add SMP support
  MAINTAINERS: add Calxeda Highbank ARM platform
  ARM: add Highbank core platform support
  ARM: highbank: add devicetree source
  ARM: l2x0: add empty l2x0_of_init
  picoxcell: add a definition of VMALLOC_END
  picoxcell: remove custom ioremap implementation
  picoxcell: add the DTS for the PC7302 board
  picoxcell: add the DTS for pc3x2 and pc3x3 devices
  ...

Fix up trivial conflicts in arch/arm/Kconfig, and some more header file
conflicts in arch/arm/mach-omap2/board-generic.c (as per an ealier merge
by Arnd).
      994c0e99
    • Linus Torvalds's avatar
      Merge branch 'next/dt' of git://git.linaro.org/people/arnd/arm-soc · 367069f1
      Linus Torvalds authored 
      * 'next/dt' of git://git.linaro.org/people/arnd/arm-soc:
  ARM: gic: use module.h instead of export.h
  ARM: gic: fix irq_alloc_descs handling for sparse irq
  ARM: gic: add OF based initialization
  ARM: gic: add irq_domain support
  irq: support domains with non-zero hwirq base
  of/irq: introduce of_irq_init
  ARM: at91: add at91sam9g20 and Calao USB A9G20 DT support
  ARM: at91: dt: at91sam9g45 family and board device tree files
  arm/mx5: add device tree support for imx51 babbage
  arm/mx5: add device tree support for imx53 boards
  ARM: msm: Add devicetree support for msm8660-surf
  msm_serial: Add devicetree support
  msm_serial: Use relative resources for iomem

Fix up conflicts in arch/arm/mach-at91/{at91sam9260.c,at91sam9g45.c}
      367069f1
    • Linus Torvalds's avatar
      Merge branch 'next/cleanup2' of git://git.linaro.org/people/arnd/arm-soc · 81a3c10c
      Linus Torvalds authored 
      * 'next/cleanup2' of git://git.linaro.org/people/arnd/arm-soc: (31 commits)
  ARM: OMAP: Warn if omap_ioremap is called before SoC detection
  ARM: OMAP: Move set_globals initialization to happen in init_early
  ARM: OMAP: Map SRAM later on with ioremap_exec()
  ARM: OMAP: Remove calls to SRAM allocations for framebuffer
  ARM: OMAP: Avoid cpu_is_omapxxxx usage until map_io is done
  ARM: OMAP1: Use generic map_io, init_early and init_irq
  arm/dts: OMAP3+: Add mpu, dsp and iva nodes
  arm/dts: OMAP4: Add a main ocp entry bound to l3-noc driver
  ARM: OMAP2+: l3-noc: Add support for device-tree
  ARM: OMAP2+: board-generic: Add i2c static init
  ARM: OMAP2+: board-generic: Add DT support to generic board
  arm/dts: Add support for OMAP3 Beagle board
  arm/dts: Add initial device tree support for OMAP3 SoC
  arm/dts: Add support for OMAP4 SDP board
  arm/dts: Add support for OMAP4 PandaBoard
  arm/dts: Add initial device tree support for OMAP4 SoC
  ARM: OMAP: omap_device: Add a method to build an omap_device from a DT node
  ARM: OMAP: omap_device: Add omap_device_[alloc|delete] for DT integration
  of: Add helpers to get one string in multiple strings property
  ARM: OMAP2+: devices: Remove all omap_device_pm_latency structures
  ...

Fix up trivial header file conflicts in arch/arm/mach-omap2/board-generic.c
      81a3c10c
    • Linus Torvalds's avatar
      Merge branch 'next/cross-platform' of git://git.linaro.org/people/arnd/arm-soc · 6585dea1
      Linus Torvalds authored 
      * 'next/cross-platform' of git://git.linaro.org/people/arnd/arm-soc:
  arm/imx: use Kconfig choice for low-level debug UART selection
  ARM: realview: use Kconfig choice for debug UART selection
  ARM: plat-samsung: use Kconfig choice for debug UART selection
  ARM: versatile: convert logical CPU numbers to physical numbers
  ARM: ux500: convert logical CPU numbers to physical numbers
  ARM: shmobile: convert logical CPU numbers to physical numbers
  ARM: msm: convert logical CPU numbers to physical numbers
  ARM: exynos4: convert logical CPU numbers to physical numbers

Fix up trivial conflict (config DEBUG_S3C_UART move/split vs addition of
ARM_KPROBES_TEST option) in arch/arm/Kconfig.debug
      6585dea1
    • Linus Torvalds's avatar
      Merge branch 'next/devel' of git://git.linaro.org/people/arnd/arm-soc · 16ee792e
      Linus Torvalds authored 
      * 'next/devel' of git://git.linaro.org/people/arnd/arm-soc: (50 commits)
  ARM: tegra: update defconfig
  arm/tegra: Harmony: Configure PMC for low-level interrupts
  arm/tegra: device tree support for ventana board
  arm/tegra: add support for ventana pinmuxing
  arm/tegra: prepare Seaboard pinmux code for derived boards
  arm/tegra: pinmux: ioremap registers
  gpio/tegra: Convert to a platform device
  arm/tegra: Convert pinmux driver to a platform device
  arm/dt: Tegra: Add pinmux node to tegra20.dtsi
  arm/tegra: Prep boards for gpio/pinmux conversion to pdevs
  ARM: mx5: fix clock usage for suspend
  ARM i.MX entry-macro.S: remove now unused code
  ARM i.MX boards: use CONFIG_MULTI_IRQ_HANDLER
  ARM i.MX tzic: add handle_irq function
  ARM i.MX avic: add handle_irq function
  ARM: mx25: Add the missing IIM base definition
  ARM i.MX avic: convert to use generic irq chip
  mx31moboard: Add poweroff support
  ARM: mach-qong: Add watchdog support
  ARM: davinci: AM18x: Add wl1271/wlan support
  ...

Fix up conflicts in:
	arch/arm/mach-at91/at91sam9g45.c
	arch/arm/mach-mx5/devices-imx53.h
	arch/arm/plat-mxc/include/mach/memory.h
      16ee792e
    • Linus Torvalds's avatar
      Merge branch 'next/board' of git://git.linaro.org/people/arnd/arm-soc · f906fb1d
      Linus Torvalds authored 
      * 'next/board' of git://git.linaro.org/people/arnd/arm-soc: (34 commits)
  ep93xx: add support Vision EP9307 SoM
  ARM: mxs: Add initial support for DENX MX28
  ARM: EXYNOS4: Add support SMDK4412 Board
  ARM: EXYNOS4: Add MCT support for EXYNOS4412
  ARM: EXYNOS4: Add functions for gic interrupt handling
  ARM: EXYNOS4: Add support clock for EXYNOS4412
  ARM: EXYNOS4: Add support new EXYNOS4412 SoC
  ARM: EXYNOS4: Add support MCT PPI for EXYNOS4212
  ARM: EXYNOS4: Add support PPI in external GIC
  ARM: EXYNOS4: convert boot_params to atag_offset
  ixp4xx: support omicron ixp425 based boards
  ARM: EXYNOS4: Add support SMDK4212 Board
  ARM: EXYNOS4: Add support PM for EXYNOS4212
  ARM: EXYNOS4: Add support clock for EXYNOS4212
  ARM: EXYNOS4: Add support new EXYNOS4212 SoC
  at91: USB-A9G20 C01 & C11 board support
  at91: merge board USB-A9260 and USB-A9263 together
  at91: add support for RSIs EWS board
  ARM: SAMSUNG: Fix mask value for S5P64X0 CPU IDs
  ARM: SAMSUNG: Fix mask for S3C64xx CPU IDs
  ...
      f906fb1d
    • Linus Torvalds's avatar
      Merge branch 'next/deletion' of git://git.linaro.org/people/arnd/arm-soc · 510597e2
      Linus Torvalds authored 
      * 'next/deletion' of git://git.linaro.org/people/arnd/arm-soc:
  ARM: mach-nuc93x: delete

Fix up trivial delete/edit conflicts in
	arch/arm/mach-nuc93x/{Makefile.boot,mach-nuc932evb.c,time.c}
      510597e2
    • Linus Torvalds's avatar
      Merge branch 'next/pm' of git://git.linaro.org/people/arnd/arm-soc · cd9a0b6b
      Linus Torvalds authored 
      * 'next/pm' of git://git.linaro.org/people/arnd/arm-soc: (66 commits)
  ARM: CSR: PM: use outer_resume to resume L2 cache
  ARM: CSR: call l2x0_of_init to init L2 cache of SiRFprimaII
  ARM: OMAP: voltage: voltage layer present, even when CONFIG_PM=n
  ARM: CSR: PM: add sleep entry for SiRFprimaII
  ARM: CSR: PM: save/restore irq status in suspend cycle
  ARM: CSR: PM: save/restore timer status in suspend cycle
  OMAP4: PM: TWL6030: add cmd register
  OMAP4: PM: TWL6030: fix ON/RET/OFF voltages
  OMAP4: PM: TWL6030: address 0V conversions
  OMAP4: PM: TWL6030: fix uv to voltage for >0x39
  OMAP4: PM: TWL6030: fix voltage conversion formula
  omap: voltage: add a stub header file for external/regulator use
  OMAP2+: VC: more registers are per-channel starting with OMAP5
  OMAP3+: voltage: update nominal voltage in voltdm_scale() not VC post-scale
  OMAP3+: voltage: rename omap_voltage_get_nom_volt -> voltdm_get_voltage
  OMAP3+: voltdm: final removal of omap_vdd_info
  OMAP3+: voltage: move/rename curr_volt from vdd_info into struct voltagedomain
  OMAP3+: voltage: rename scale and reset functions using voltdm_ prefix
  OMAP3+: VP: combine setting init voltage into common function
  OMAP3+: VP: remove unused omap_vp_get_curr_volt()
  ...

Fix up trivial conflict in arch/arm/mach-prima2/l2x0.c (code removal vs
edit)
      cd9a0b6b
    • Linus Torvalds's avatar
      Merge branch 'next/timer' of git://git.linaro.org/people/arnd/arm-soc · ac5761a6
      Linus Torvalds authored 
      * 'next/timer' of git://git.linaro.org/people/arnd/arm-soc:
  clocksource: fixup ux500 build problems
  ARM: omap: use __devexit_p in dmtimer driver
  ARM: ux500: Reprogram timers upon resume
  ARM: plat-nomadik: timer: Export reset functions
  ARM: plat-nomadik: timer: Add support for periodic timers
  ARM: ux500: Move timer code to separate file
  ARM: ux500: add support for clocksource DBX500 PRCMU
  clocksource: add DBX500 PRCMU Timer support
  ARM: plat-nomadik: MTU sched_clock as an option
  ARM: OMAP: dmtimer: add error handling to export APIs
  ARM: OMAP: dmtimer: low-power mode support
  ARM: OMAP: dmtimer: skip reserved timers
  ARM: OMAP: dmtimer: pm_runtime support
  ARM: OMAP: dmtimer: switch-over to platform device driver
  ARM: OMAP: dmtimer: platform driver
  ARM: OMAP2+: dmtimer: convert to platform devices
  ARM: OMAP1: dmtimer: conversion to platform devices
  ARM: OMAP2+: dmtimer: add device names to flck nodes
  ARM: OMAP: Add support for dmtimer v2 ip
      ac5761a6
    • Linus Torvalds's avatar
      Merge branch 'next/driver' of git://git.linaro.org/people/arnd/arm-soc · 25498e5b
      Linus Torvalds authored 
      * 'next/driver' of git://git.linaro.org/people/arnd/arm-soc:
  hw_random: add driver for atmel true hardware random number generator
  ARM: at91: at91sam9g45: add trng clock and platform device
  MX53 Enable the AHCI SATA on MX53 SMD board
  MX53 Enable the AHCI SATA on MX53 LOCO board
  MX53 Enable the AHCI SATA on MX53 ARD board
  AHCI Add the AHCI SATA feature on the MX53 platforms
  Fix pata imx resource
  ARM: imx: Define functions for registering PATA
  ARM: imx: Add PATA clock support
  ARM: imx: Add PATA resources for other i.MX processors
  imx: efika: Enable pata.
  imx51: add pata clock
  imx51: add pata device

Fix up trivial conflict (new selects next to each other from separate
branches for EFIKA_COMMON) in arch/arm/mach-mx5/Kconfig
      25498e5b
    • Linus Torvalds's avatar
      Merge branch 'next/cleanup' of git://git.linaro.org/people/arnd/arm-soc · 95241450
      Linus Torvalds authored 
      * 'next/cleanup' of git://git.linaro.org/people/arnd/arm-soc: (125 commits)
  ARM: mach-mxs: fix machines' initializers order
  mmc: mxcmmc: explicitly includes mach/hardware.h
  arm/imx: explicitly includes mach/hardware.h in pm-imx27.c
  arm/imx: remove mx27_setup_weimcs() from mx27.h
  arm/imx: explicitly includes mach/hardware.h in mach-kzm_arm11_01.c
  arm/imx: remove mx31_setup_weimcs() from mx31.h
  ARM: tegra: devices.c should include devices.h
  ARM: tegra: cpu-tegra: unexport two functions
  ARM: tegra: cpu-tegra: sparse type fix
  ARM: tegra: dma: staticify some tables and functions
  ARM: tegra: tegra2_clocks: don't export some tables
  ARM: tegra: tegra_powergate_is_powered should be static
  ARM: tegra: tegra_rtc_read_ms should be static
  ARM: tegra: tegra_init_cache should be static
  ARM: tegra: pcie: 0 -> NULL changes
  ARM: tegra: pcie: include board.h
  ARM: tegra: pcie: don't cast __iomem pointers
  ARM: tegra: tegra2_clocks: 0 -> NULL changes
  ARM: tegra: tegra2_clocks: don't cast __iomem pointers
  ARM: tegra: timer: don't cast __iomem pointers
  ...

Fix up trivial conflicts in
  arch/arm/mach-omap2/Makefile,
  arch/arm/mach-u300/{Makefile.boot,core.c}
  arch/arm/plat-{mxc,omap}/devices.c
      95241450
    • Linus Torvalds's avatar
      Merge branch 'next/fixes' of git://git.linaro.org/people/arnd/arm-soc · 68e24ba7
      Linus Torvalds authored 
      * 'next/fixes' of git://git.linaro.org/people/arnd/arm-soc: (28 commits)
  ARM: pxa/cm-x300: properly set bt_reset pin
  ARM: mmp: rename SHEEVAD to GPLUGD
  ARM: imx: Fix typo 'MACH_MX31_3DS_MXC_NAND_USE_BBT'
  ARM: i.MX28: shift frac value in _CLK_SET_RATE
  plat-mxc: iomux-v3.h: implicitly enable pull-up/down when that's desired
  ARM: mx5: fix clock usage for suspend
  ARM: pxa: use correct __iomem annotations
  ARM: pxa: sharpsl pm needs SPI
  ARM: pxa: centro and treo680 need palm27x
  ARM: pxa: make pxafb_smart_*() empty when not enabled
  ARM: pxa: select POWER_SUPPLY on raumfeld
  ARM: pxa: pxa95x is incompatible with earlier pxa
  ARM: pxa: CPU_FREQ_TABLE is needed for CPU_FREQ
  ARM: pxa: pxa95x/saarb depends on pxa3xx code
  ARM: pxa: allow selecting just one of TREO680/CENTRO
  ARM: pxa: export symbols from pxa3xx-ulpi
  ARM: pxa: make zylonite_pxa*_init declaration match code
  ARM: pxa/z2: fix building error of pxa27x_cpu_suspend() no longer available
  ARM: at91: add defconfig for at91sam9g45 family
  ARM: at91: remove dependency for Atmel PWM driver selector in Kconfig
  ...
      68e24ba7
    • Arnd Bergmann's avatar
      Merge branch 'imx/imx6q' into next/soc · abc3f126
      Arnd Bergmann authored 
      Conflicts:
	Documentation/devicetree/bindings/arm/fsl.txt
	arch/arm/Kconfig
	arch/arm/Kconfig.debug
	arch/arm/plat-mxc/include/mach/common.h
      abc3f126
    • Arnd Bergmann's avatar
      Merge branch 'picoxcell/soc' into next/soc · b8df0ea2
      Arnd Bergmann authored
      b8df0ea2
    • Arnd Bergmann's avatar
      Merge branch 'highbank/soc' into next/soc · 884897e6
      Arnd Bergmann authored 
      Conflicts:
	arch/arm/mach-mxs/include/mach/gpio.h
	arch/arm/mach-omap2/board-generic.c
	arch/arm/plat-mxc/include/mach/gpio.h
      884897e6
  3. 01 Nov, 2011 22 commits
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